1. Field of the Invention
The present invention relates to an underwater jacket, which may be used for scuba diving of the like.
2. Description of the Prior Art
Underwater jackets for use in scuba diving include an outside waterproof cloth and an inside waterproof cloth, which are put one upon the other and connected together at marginal edges thereof by sewing to form a jacket body into which air may be injected.
The jacket body is inflated by injecting air thereinto, and, consequently, if the jacket body is formed by connecting the outside and inside cloths to each other only at their maginal edges the jacket body will inflate into a flat mat form, which can hardly fit to a body of a user. In order to make the jacket easily fittable to a user's body, the jacket is usually formed with a portion or portions where the combined cloths can be easily folded or curved. Such portion corresponds, for example, to a boundary portion between a front side part and a rear side part of the jacket body.
Heretofore, it has been proposed to form such an easily foldable portion by welding. FIGS. 3 and 4 illustrate such a construction, in which an outside cloth and an inside cloth are connected together by means of welded portions P at positions where the jacket body is to be folded.
According to the construction that is shown in FIGS. 3 and 4, the outside cloth and the inside cloth are partially connected together by the welded portions P. Therefore, when air is injected into the jacket body, air does not enter into the welded portions P, and thus these portions can be easily folded. This construction has the advantage that the jacket body can be easily folded at the weld portions. However, a disadvantage of this construction is that the parts of the outside and inside cloths, which are connected together only by welding, may be separated during continued use of the jacket. If the cloths are separated, the jacket body becomes inflated at the welded parts, so that is becomes difficult to fold the jacket body at the positions where the jacket body is to be folded.